The present invention relates to apparatuses for handling sheet-like articles, and more particularly, to apparatuses for stacking envelopes into stacks of a predetermined number, packing the stacks into cartons, sealing the cartons and transporting the sealed cartons to an area for loading into shipping containers.
The manufacture of envelopes of the type used to enclose folded documents such as letters, bills, and the like has been automated to the point wherein a single apparatus receives a web unwound from a roll of paper, cuts the web into planks, imprints, folds, and glues the blanks to form envelopes, and arranges the folded and glued envelopes at a discharge station in a horizontal column. An example of such a machine is a rotary reel-fed envelope machine manufactured by Winkler & Dunnebier. Once the envelopes are manufactured by such a machine, they must be separated into groups of a predetermined number, such as 50 or 100 envelopes, loaded into set-up cartons, and the cartons loaded into shipping containers. There also exist devices for separating the envelopes in the horizontal column into groups.
However, presently the groups of envelopes must be manually removed from a horizontal column formed by the envelope machine and placed into the open tops of set-up cartons. The cartons are then transported to a sealing machine and the cartons discharged from the sealing machine must be manually loaded into shipping containers.
In view of the unavoidable hazards present with the manual loading of envelopes into a set-up carton due to the properties of the paper forming the envelopes, and the chance for error resulting from the repeated performance of a manual task, it is desirable to automate this portion of the envelope handling system as well. Suggestions for such automation may be found in several patents.
For example, the Yamada et al. U.S. Pat. No. 4,511,136 discloses a sheet handling device in which a spider feeder feeds sheets traveling horizontally from an upper level conveyor and deposits them into a vertical stack on a lower level conveyor. The apparatus includes reciprocating fingers which are projectable into and out of a sheet stacking zone so that sheets may be collected above the lower level conveyor in order to provide sufficient time for the lower level conveyor to index a completed stack away from the stacking zone. A disadvantage with such a device is that it is incapable of handling freshly folded envelopes which contain air and must be compressed to a height which approximates the thickness of the carton into which they will be packed.
A device for compressing stacks is disclosed in the Sasaki et al. U.S. Pat. No. 4,339,119. That patent discloses a sheet stacking apparatus in which reciprocating rods are projected into a stacking zone to catch sheets discharged by an upper level conveyor and accumulate the sheets into a stack. The apparatus includes a "beat member" which presses against the sheets and compresses them against the rods.
A disadvantage with the device disclosed in the Sasaki et al. patent is that it cannot be used with a spider feeder mechanism such as that shown in the Yamada et al. patent. A spider feeder mechanism is an important component in any such system since it provides a mechanism for receiving envelopes or other sheet-like articles from a high level conveyor and depositing them into a vertical stack at a lower level without permitting the envelopes or articles to tumble.
In order to automate that portion of the system in which stacks of articles are packed into set-up cartons, it is necessary to provide a mechanism which removes the articles from a conveyor and feeds them into the carton. Such a device is suggested in the Lister et al U.S. Pat. No. 4,062,169. That patent discloses an apparatus for packing semi-compressable articles, such as towels, into preformed plastic bags open at one end. The apparatus includes a conveyor which transports the stack of towels to a reciprocating ram which, in turn, transports the stack sidewardly through a pair of gate members and into the preformed bag. The gate members include converging top and side walls for compressing and guiding the stack as it enters the bag.
A disadvantage of such a device is that it cannot be used with other automated equipment of the type which automatically sets up a carton and, subsequent to the carton being loaded with articles, transports the carton to a sealing device. In contrast, the Lister et al. apparatus requires that bags manually be placed in registry with the gate members and, after loading, be manually removed from engagement with the gate members.
Accordingly, there is a need for a system for receiving folded and glued envelopes from a reel-fed envelope machine, stacking the envelopes into vertical stacks into a bucket conveyor, packing the stacks of envelopes into set-up cartons, sealing the cartons, and transporting the sealed cartons to an area for loading in shipping containers. Such a system should be as fully automated at possible and preferably should be capable of use with currently available machines.